The present invention relates to a premixer for gas turbine combustors, a premixing method for gas turbine combustors, a gas turbine combustor and a combustion method for gas turbine.
In a gas turbine combustor and a combustion method for gas turbines, in order to reduce exhaust amount of NOx which is an air pollution material, an application of premixing combustion method is now progressing in which fuel and air premixed before the fuel is introduced into a combustion chamber. For example, as disclosed in JP-A-3 175211 (1991), a diffusive combustion showing excellent stability is assigned at the center portion of the combustion chamber and a premixing combustion showing excellent low NOx property is assigned at the outer circumferential side thereof, thereby, NOx reduction is achieved. In this disclosure, air sent from a compressor passes between a combustor outer cylinder and a combustor liner and flows in respectively such as a combustion chamber and a pre-mixer.
Diffusive combustion use fuel is injected from a diffusion fuel nozzle into the combustion chamber to form stable diffusive flame and premixing use fuel is injected from a premixing fuel nozzle into an annular premixer to mix air and to from premixed gas.
The above premixed gas flows out into the combustion chamber to form premixing flame. The generated high temperature combustion gas is introduced into a turbine to perform works and thereafter is exhausted.
In a low NOx combustor making use of such premixing combustion, formation of uniform premixed gas greatly affects the low NOx performance. In particular, in the above conventional example which is structured in such a manner that the air flow makes a U turn at the inlet of the premixer, a drift with regard to air flow is likely caused which makes difficult to form a uniform mixing gas. Namely, for such measure it requires great attention of advancing the mixing in the premixer.
With regard to air flow in such premixer, JP-A-60-223578 (1985) and JP-A-2-267419 (1990), for example, disclose technical measures therefor.
JP-A-2-267419 (1990) discloses such a technique that a partition wall is provided for every nozzles so as to separate the same in the circumferential direction in the premixer, inlet windows of which opening is deviated are provided so that premixing combustion use air flows in an deviated manner, thereby a swirl component is caused in the premixing combustion use air and the mixing with fuel is advanced. However, the disclosure does not fully takes into account the relationship between the window configuration and the fuel nozzles.
An object of the present invention is to provide a premixer for gas turbine combustor, a premixing method for gas turbine combustors, a gas turbine combustor and a combustion method for gas turbines which uniformalize the premixing and show an excellent low NOx performance.
A gas turbine combustor according to the present invention comprising diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame, outer and inner walls which from an annular premixing flow passage and premixing nozzles which are disposed in the premixing flow passage and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber, is characterized in that a plurality of the premixing nozzles are arranged in the premixing flow passage; opening portions permitting air to flow in are provided at the outer wall so that the air flowed into the premixing flow passage forms swirling flow with respect to the premixing nozzles; and the opening portions are disposed in circumferential direction and are provided one for every adjacent two premixing nozzles.
A gas turbine combustor according to another aspect of the present invention comprising diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame, outer and inner walls which form an annular premixing flow passage and a premixing nozzles which are disposed in the premixing flow passage and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber, is characterized in that a plurality of the premixing nozzles are arranged in the premixing flow passage; opening portions permitting air to flow in are provided at the outer wall so that the air flowed into the premixing flow passage forms swirling flow with respect to the premixing nozzles; and the opening portions are disposed in circumferential direction and are provided one for every adjacent two premixing nozzles and the rotating directions of the swirling flows for the respective two premixing nozzles are caused to direct opposite direction each other.
A gas turbine combustor according to still another aspect of the present invention comprises: diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame; an inner cylinder arranged outside the diffusive combustion nozzles; a plurality of premixing nozzles which are arranged outside the inner cylinder circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber; and means for forming respective swirling flows of different rotating direction for the adjacent two premixing nozzles in circumferential direction.
A gas turbine combustor according to a further aspect of the present invention comprising diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame, outer and inner walls which form an annular premixing flow passage and premixing nozzles which are disposed in the premixing flow passages and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber, is characterized in that a plurality of the premixing nozzles are arranged in the premixing flow passage; and opening portions permitting air to flow in are provided at the outer wall so that the air flowed into the premixing flow passage forms swirling flows for the adjacent two premixing nozzles.
A gas turbine combustor according to a still further aspect of the present invention comprising diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame, outer and inner walls which form an annular premixing flow passage and premixing nozzles which are disposed in the premixing flow passage and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber, is characterized in that a plurality of the premixing nozzles are arranged in the premixing flow passage; opening portions permitting air to flow in into the premixing flow passage are provided at the outer wall and at portions between adjacent two premixing nozzles in the circumferential direction; and isolation wall members which are provided respectively at both sides of the adjacent two premixing nozzles in the circumferential direction.
A gas turbine combustor according to a still further aspect of the present invention comprises: diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame; an inner cylinder arranged outside the diffusive combustion nozzles; a plurality of premixing nozzles arranged outside the inner cylinder in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber; means for forming respective swirling flows of different rotating direction for the adjacent two premixing nozzles in circumferential direction; and a member which surrounds the adjacent two premixing nozzles in the circumferential direction along the axial direction thereof.
A gas turbine combustor according to a still further aspect of the present invention comprising diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame, outer and inner walls which form an annular premixing flow passage and premixing nozzles which are disposed in the premixing flow passage and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber, is characterized in that a plurality of the premixing nozzles are arranged in the premixing flow passage; and opening portions permitting air to flow in are provided at the outer wall so that the air flowed into the premixing flow passage forms swirling flows with respect to the premixing nozzles, thereby, the rotating directions of the swirling flows for the respective two premixing nozzles are caused to direct opposite directions each other.
A gas turbine combustor according to a still further aspect of the present invention comprises diffusive combustion nozzles which inject fuel and air into a combustion chamber and form a diffusive combustion flame, outer and inner walls which form an annular premixing flow passage and premixing nozzles which are disposed in the premixing flow passage and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into the combustion chamber, wherein a plurality of the premixing nozzles are arranged in the premixing flow passage; opening portions permitting air to flow in are provided at the outer wall so that the air flowed into the premixing flow passage forms swirling flow with respect to the premixing nozzles; and each of the opening portions is configured in nearly a triangular shape in such a manner either that the opening broadens in the main air stream direction prior to flowing into the premixer or that the opening decreases in the main air stream direction prior to flowing into the premixer; and the rotating directions of the swirling flows for the respective two premixing nozzles are caused to direct opposite directions each other.
A gas turbine combustor use premixing device according to one aspect of the present invention comprising a plurality of premixing nozzles which are arranged in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into a combustion chamber, is characterized in that one air flow inlet for every adjacent two premixing nozzles is provided so that a swirling flow is formed for the respective adjacent two premixing nozzles in the circumferential direction.
A gas turbine combustor use premixing device according to another aspect of the present invention comprising a plurality of premixing nozzles which are arranged in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into a combustion chamber, is characterized in that one air flow inlet for every adjacent two premixing nozzles is provided so that swirling flows of which rotating directions are opposite each other are formed for the respective adjacent two premixing nozzles in the circumferential direction.
A gas turbine combustor use premixing device according to still another aspect of the present invention comprising a plurality of premixing nozzles which are arranged in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into a combustion chamber, is characterized in that means is provided which forms swirling flows of which rotating directions are different for the respective adjacent two premixing nozzles in the circumferential direction.
A premixing method for a gas turbine combustor according to one aspect of the present invention comprising a plurality of premixing nozzles which are arranged in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into a combustion chamber, is characterized in that air is flown from air flow inlets each being provided for every adjacent two premixing nozzles in the circumferential direction, and swirling flows are formed around the respective adjacent two premixing nozzles.
A premixing method for a gas turbine combustor according to another aspect of the present invention comprising a plurality of premixing nozzles which are arranged in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into a combustion chamber, is characterized in that air is flown from air flow inlets each being provided for every adjacent two premixing nozzles, and swirling flows of which rotating directions are opposite each other are formed around the respective adjacent two premixing nozzles.
A premixing method for a gas turbine combustor according to still another aspect of the present invention comprising a plurality of premixing nozzles which are arranged in circumferential direction and form a premixing combustion flame by injecting premixed gas formed by premixing fuel and air into a combustion chamber, is characterized in that one air flow inlet for every adjacent two premixing nozzles is provided so that swirling flows of which rotating directions are different each other are formed around the respective adjacent two premixing nozzles in the circumferential direction.